Internet

• Internet

  • Most well-known Wide Area Network
  • A collection of interconnected networks spanning the world
  • Not the same as the World Wide Web, which is just a service on the internet.
• Web addresses, which are easier for humans to remember, are cionverted to IP addresses for routers by a domain name server (DNS)
• An IP address, or simply an IP, is a unique address that identifies a device on the internet or a local network - it allows a system to be recognised by other systems connected by other systems connected via the internet protocol.
• A router is an essential hardware component of the internet.

  • Its main purpose is to connect multiple networks
  • It forwards information (data packets) destined for either its own network or other networks.
• Data sent across networks is spilt up into packets for transmission

  • The header of each packet contains various information including a source and destination IP address.
  • It also contains a sequence ID, which means packets that arrive out of order can be reassembled into the correct order once they arrive at the destination.
• Here, is a home network connected via a wireless router

  The home router is connected to an internet service provider (ISP)

  Our ISP is connected to a domain name server (DNS) and other routers within the backbone of the internet.

  
• What is a static IP address?


  Devices requiring constant network access
• What is a dynamic IP address? 


  It is issued by the network when the device connects. The IP address is temporary and is returned to a pool of available addresses when the device disconnects.
• What is the DNS system?


  The domain name server is required to look up the IP address of the given URL.